1. Field of the Invention
This invention relates to a water setting (water solidifying) paper or a high water-absorbency material in sheet form containing high water-absorbency resin.
2. Description of the Prior Art
It is generally known that paper produced from paper-making materials containing carboxymethylcellulose (CMC-H) or corboxyethylcellulose (CEC-H), and the respective aluminum salt, barium salt, zinc salt, tin salt and manganese salt thereof (CMC-Al, CMC-Ba, CMC-Zn, CMC-Sn, CMC-Mn, CEC-Al, CEC-Ba, CEC-Zn, CEC-Sn, CEC-Mn) are water-soluble or have the property of becoming rapidly dispersed in water. Water-soluble paper is utilized as the paper for secret documents and for water-soluble labels. Methods for manufacturing paper that is water-soluble or which disperses rapidly in water are disclosed in, for example, Japanese Laid-open Patent No. 38-(1963) 25,159, Japanese Laid-open Patent No. 39-(1964) 152, Japanese Laid-open Patent No. 40-(1965) 968, Japanese Laid-open Patent No. 42-(1967) 2,925, Japanese Laid-open Patent No. 43-(1968) 1,214 and Japanese Laid-open Patent No. 48-(1973) 27,605.
Also, because high water-absorbency resins of the grafted-starch series, cellulose series and polyacrylic acid series have higher water-absorbency than conventional water-absorbing materials such as cotton, cloth, sponge and tissue paper, they are used in sanitary napkins, paper diapers, underpads and the like.
High water-absorbency resin is used by encapsulation or inclusion of the resin in non-woven fabrics or pulp products such as tissue paper and the like which are then disposed at an inner portion of the sanitary napkin, paper diaper and so forth, so that the water content of the voided urine and the like passing through the paper is absorbed and solidified at the inner portion, with even the surface moisture of the paper itself being absorbed, providing the products with a clean feeling in use.
Disposal following urination has been a problem in the case of conventional urine containers such as urine bottles and portable toilets, the drawback being that urine that has been collected in the container is spilled when the container is moved or shaken, soiling the surroundings. To eliminate this drawback, conventionally high water-absorbency resin has been placed inside the urine bottle or other such urine container to solidify the urine. Another method that has been advanced has involved encapsulating the said high water-absorbency resin inside a non-woven fabric or pulp product, and inserting the thus-prepared product into the urine container.
However, because with this method the high water-absorbency resin is enveloped in pulp, it becomes interlocked with the long pulp fibers and is not easily dissolved. And with respect also to disposal, because it does not readily dissolve in water, it is not possible to flush it down flush toilets. Therefore the only way the product could be dissolved after use was by means of formerly used methods such as incineration.
With the method involving the spreading of high water-absorbency resin as it is in the urine container, the spreadig took time, and as the resin was inserted in particulate form, it had the drawback of being inconvenient to store and handle. Then again, because particulate resin reacts with small amounts of liquid and sets starting at the surface, resin which lies thereunder and not exposed to the surface loses any chance of being involved in the reaction owing to the setting of the surface resin. As a result, urine in many cases remains in the urine container in a state of incomplete reaction (agglomerate state). In order to activate it, it is necessary to stir up the underlying resin to bring it to the surface; but as this is unhygienic, it is usually disposed of in its entirety.